<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
</head>
<body>
<script>
  function Person(name) {
    this.name = name;
  }
  Person.prototype.sayHi = function () {
    console.log('你好');
  }
  function Animal(category) {
    this.category = category;
  }
  Animal.prototype = new Person('赵四');
  var ani = new Animal('土拨鼠');
</script>
</body>
</html>
